Automatic change-speed gear



Jan. 2, .1940. H. METZLER AUTOMATIC CHANGE-SPEED GEAR Filed Nov. 11, 1936 8 Sheets-Sheet l 'ynvenlor.

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H. METZLER Jan. 2 1940.

-SPEED GEAR Filed NOV. 11, 1936 AUTOMATIC CHANGE a Sheets-Sheet a Jan. 2, 1940. H. METZLER AUTOMATIC CHANGE -SPEED GEAR Filed Nov. 11, 1936 a Sheets-Sheet 4 7 Jan. 2, 1940. A H, METZLE 2,185,602

AUTOMATIC CHANGE-SPEED GEAR Filed Nov. 11, 1936 8 Sheets-Sheet 5 Hg. 7. is Fig. 8.

J-m z, 1940. H, METZL R 2,185,602

AUTOMATIC CHANGE-SPEED GEAR Filed Nov. 11, 1936 V 8 Sheets-Sheet 6 Jan. 2, 1940. H. METZLER AUTOMATIC CHANGE-SPEED GEAR Filed Nov. 11, 1936 8 Sheets-Sheet 7 Jan. 2, 1940. H. METZLER AUTOMATIC CHANGE-SPEED GEAR 8 Sheets-Sheet 8 Filed Nov. 11, 1936 Patented 1.... 2, 1940 UNITED STATES PATENT- oFnc-E 2,185,602 AUTOMATIC CHANGE-SPEED GEAR Heinrich Metzler. Felflkirch, Voralberg, A111 Application November 11, 1936, Serial no. 110.2... In Germany November 13, 1835 a driven shaft.

A preferred form of the invention is illustrated in the attached drawings, wherein:

Figure 1 is a plan view of the invention seen from below and partly in section along line l-l of Figure 2. I

Figure 2 is a view turned 180 and is a section on line 2-2 of Figure 1,

Figure 3 is a detail of a so-called gate,

Figure 4a shows an arrangement for a low number of revolutions, at maximum load, and is taken on line 4--4 of Figure'5,

Figure 4b is a view similar to above but at medium load,

Figure 5 is a view taken on line 55 of Figure 4a.

Fig. 6 is a section on the line 6- 6 of Fig. 7 showing an arrangement for low torque transmission.

I Fig. 7 is a longitudinal section on the line of Fig. 6.

Fig. 8 is a section on the line 8-8 of Fig. 7.

Figure 9 is a side elevational view along line 99 of Figure 10,

Figure 10 is a broken plan view of a detail represented in Figure 9, of that end which is turned towards the driven shaft of the machine,

Figure 11 is .a sectional detail taken on line ll--ll of Figure 12,

Figure 12 shows a front view of a detail,

Figure 13 shows a front view of a detail,

Figure 14 is a cross-section of another detail for hand shifting,-

Figure 15 is a plan view means.

Figure 16 is a section of a detail taken on line l6--I6 of Figure 1'7,

Figure 17 is a section of a detail on line l'||| of Figure 16,

' Figure 18 is a similar partial plan view,

Figure 19 shows two detail views arranged side by side, partially cut corresponding to line Ill-49 of Figure 18, and

Figure 20 is an additional plan view of the device, in which different parts are arranged difierentiy, as described in the text.

Referring first to Figures 1-3, 9-13, 16-20, the shaft 8 is intended to be connected with the part of hand-shifting '1 Claims. (01. 74-331 to be dri n, for instance with the differential of amotor-vehicle drive wheels. The shaft 23 is meant to connect with the motive power source. The middle part of shaft l is provided with longitudinal grooves 35, provided in the circumfer- 5 ence of the shaft, as shown in Figure 1 and Figure 20.

Into these grooves 35 enter splines 2a provided in the middle of part 2. (Figs. 11,- 12 and 13). Due to the fact that the splines 2a reach into the grooves 35, part 2 cannot be turned relative to the shaft I, but can only be displaced in an axial direction thereon. In part 2, holes 2b have been provided radially and into which bolts 20 are slid. The bolts 2c penetrate into driver 15 rollers 3, which, as for instance in Figures 1, 11, 12 and 13, are formed in the shape of conical cylinders. The rollers 3, as may be seen by looking at the drawings, are pivoted on bolts 20 and mounted to rotate in relation to part 2. In 0 order to prevent the bolts 2c from flying out, as a result of centrifugal forces, a ribbon 2d has been fastened around part 2, as illustrated in Figures 1, 11, 12 and 20. The part 2 may be shaped in the form of a casing or drum as may 25 be seen from Figures 1, 11, 12 and 20, or it may be formed as a double-lever, as seen from Figure 13. In the latter case, in order to secure the bolt 2c in place, bows 2e are fastened around the outer area of part 2. These bows are made of steel-sheeting or of some other suitable material and made fast by screws 2 or the like. The part of shaft I which lies behind that portion carrying the grooves has been provided with a worm or thread Ia onto which nuts 33 have 35 been threaded. Between the nuts 33 and the part 2, a spring 4 has been placed. Between shaft I and shaft 23, a shaft 5 has been made provision for (see Fig.1). The end of shaft 5,

which" is nearest to shaft I, is fitted with a concave disc 6 (see Fig. 9), having projections I,

pointing in the direction of the rollers 3.

Co-axial with the'shaft 5 are hollow shafts 8 and"9 on the ends of which adjacent to the drivers are the concaved sleeve-like discs I!) and H which are likewise provided with'tappet-like elevated portions I 2 and H. The elevated portions l2 extend beyond the elevated portions 'l, and the elevated portions l4 extend beyond the elevated portions l2.

Secured on the hollow shaft 8 is a toothed v wheel 15. Secured on the hollow shaft 9 is the toothed wheel 15. The toothed wheel I5 is in engagement with the toothed wheel [9 connected by W of I free wheel connection 11 with the intermediate. shaft l8. The toothed wheel l6 engages the toothed wheel 2! connected by way of a free wheel connection 20 with the intermediate shaft i8.

Around the circumference of shaft 5, at the end which is nearest to shaft 23, splines 51: have been arranged along which a coupling member 22, splined thereon, can beslid axially. (See Figures 1, 9 and 10.) The changing of position ofmember 22 is done with a lever 46 which engages member 22 by means of a groove 22a with which the latter is provided. The manner in which this is done is to be described later on. The end of shaft 23 is provided with teeth 24, the reduced end 24a of which pointing towards 22 carries teeth which are smaller in height. On part 22 are inside teeth 22b which correspond to teeth 26a. If the member 22, from a position as illustrated in Figure 1, "is pushed over or along part 2411, the inside teeth 22b engage or mesh into teeth 2% in such a way that thro'ugh shaft 23 over 24 and Ma, part 22 and with it shaft 5 itself, is taken along. In Figure .9 part 22' is shown in such a position whereby. there is no connection between shafts 23 and 5. The teeth 24 of shaft 23 are continuously engaging gear 25, the latter of which is fastened onto the intermediate shaft it.

The free-wheel connections I '1 and 20, as shown in Figure 1, and in moredetail in Figures 16 and 1'7, are connected with the intermediate shaft and the gears in the following manner:

The intermediate shaft lB'has splines 34 into which slide the teeth Ila of parts 81b, which are movable on shaft 08 in axial direction. The parts i'ib are provided with a star-like sprocket having projections H0 which are all of thesame height. The spaces l'ld between each one of the projections We are in the form of an outward curvature (see Fig. 16 and Fig. 17), and in which a cylinder lie has been placed which, by means of a spring-pressed part IT can be urged towards the high-point of the curved area Md.

The part l'lb is provided with an enlargement ,lig upon which the corresponding gears 99 and and respectively are mounted and around which they can turn. Upon theends of parts lib pointing towards the rollers 3, a collar iii is mounted, having a circumferential groove 63 and secured by screws or the like. The part ill) is shouldered at point ilk against which the part i'iz' is pressed to leave the cylinders i'le free.

As a consequence of the positions of. parts illustrated in Figure 1, the following automatic shifting positions can be had:

With a moderate load on the shaft l the drivers 3 and thus the parts 2 and l are entrained by the elevated portions 7; There is thus efl'ected direct transmission of power, the disc extensions it and H of the hollow shafts being driven by the drivers engaging the elevated portions 92 and i l, the hollow shafts 8 and 9 and the toothed wheels l5 and it being rotated accordingly, the toothed wheels 95 and i6 rotating at the same speed as the shafts l and 5 and the toothed wheel 2 As the toothed wheel 2% is smaller than the toothedwheel 25 secured on the intermediate shaft 58, the intermediate shaft it rotates at a lower speed than the shafts 5 and 23. As in consequence of the transmission ratio, the toothed wheelsw and 2! in engagement with the toothed wheels l5 and I6 rotate at a higher speed than the intermediate shaft E8, the free wheel connections I? and 26 come into operation so that there is no tran m ssi n of power from the intermediate shaft to the more rapidly rotating toothed wheels 19 and 2|.

If the load is increased, then in consequence of the inclination of the elevated portions 1, the

drivers 3 are displaced in the direction of the arrow 21, overcoming the spring 4; the elevations I slide beneath the drivers 3 and the drivers now act on the next larger elevated portions 12.. At thistime the hollow shaft 8, the toothed wheel l6 secured thereon, and the toothed wheel 2| meshing with the toothed wheel l6 will be checked in consequence of the load on I, 2 and 3, so that a connection is effected of the toothed wheel 2| by way of the free wheel connection 20' with the intermediate shaft IS, with the toothed wheel 25 secured on the latter, with the toothed wheel 24 meshing with the toothed wheel 25, and with the shaft stump 23 rigid with the toothed wheel 24; In consequence of the reduction ratio between the toothed wheels 24- and 25, the inter-' mediate shaft I8 is rotated at a lower number of revolutions than the-shaft stump This lower number of. revolutions is transmitted with a correspondingly increased torque from the elements 2|, l6, s, m, I2, 3, 2 to the shaft I, amiss along the inclines of the elevated portions l2,

ilvith further increased load the drivers slide,

and are displaced further in the direction of the arrow 27, so that finally the-elevated portions 82 slide beneath the drivers, and only the still larger elevated portions l4 act on the drivers 3.

There is now eflected checking of the hollow shaft 2 9 and of the toothed wheels l5 and i9, and connection isefi'ected between the toothed wheel 99 by way of. the free wheel connection it with the intermediate shaft 58 and by way of the intermediate shaft with the toothed wheels 25 and 2t and the shaft stump 23,- The shaft 5 and the hollow shaft t now run at a higher speed than the hollow shaft 9, but these parts are no longer connected with the drivers 3 as the elevated portions 7 and i2 move freely beneath the drivers 3. a The pitch or the cam form of the elevated portions E, 62 and it is such, or the tappet-like elevated portions 7, i2 and are so bulged that, at the several transmission stages, the forces acting axially through the spring 4 on the drivers 3 balance the forces acting radially and caused by the load on the drivers 8, until the loadfor the stage actually in operation is so increased or diminished that by axial displacement of the drivers a changeover is effected to the next higher or the next lower stage.

The axlai spring thrust is taken up by bearings 30 and 32 which are constructed to take up combined radial and axial" thrusts, and may be formed for example as tapered roller bearings.

In order, instead of automatic changeover to be able to efiect variation at will of the stages of transmission, as is desirable for example in the adaptation of the gearing to power vehicles, when coasting, with a steepinclined, the toothed wheels l9 and 20 provided with free wheel connections are arranged to be axially slidable on the intermediate shaft IS in grooves 34, and beside each of these toothed wheels there is provided a toothed wheel 29 or 30 of the same size slidable in the same grooves 34 or the like, or the free wheel connections are adapted to be individually locked, i. e., rendered inoperative, so that the toothed wheels provided with the free wheel connections may be rigidly coupled with l8.

The blocking-device for the free-wheel connections can be executed according to'Fig. 18 and 19, descriptionof which follows:

Upon shaft 13 are mounted gears l8a which are securely fastened thereon. On shaft I8, longitudinal grooves 34 have also been provided, in

' which sliding, wedge-like grip member I'Ib are arranged-to be shifted in axial direction. Thegears l9 and 2|. respectively are connected with part llm which is freely ournalled on "b on one side, and with another part lln, provided with inside teeth, on the'other side, connection being made by screwing or some other suitable manner. The screw-pressure on parts l'lm and Mn is therefore taken up by the gears l9 and 2|, thereby leaving the free-wheel cylinders lle suflicient play in order to move between parts i 1m and I'm. The parts I'Im are provided with grooves I10 which run all around into which shifting members not shown in Fig. 19 may engage. If by means of the shifting members engaging in No, a shifting in axial direction has taken place, it follows that part llm at the same time also takes part l'lb along, because the starlike members We, of part l'lb, are located in between the parts l'|m and- I'm. The free-wheels and the tooth-wheels l9 and 2l belonging thereto, may be moved in axial direction upon shaft by shifting members. engaging into the grooves 110 in such a manner that the inside teeth of part I In can be engaged with the outside-teeth of part l8a, Fig. 19. In that case, the freewheel 20 belonging to gear 21 has been blocked.

In case of a free-wheel being shifted with the gear belonging thereto, in axial direction, in whereby the inside gear I'ln fastened to it no longer engages into gear lBa fastened on l8,-the blocking of the free-wheel is suspended as seen in Fig. 19. In Fig. 19, the gears l5 and I6 havebeen indicated in broken-lines.

The free-wheel blocking may be executed also in such manner whereby part l'lh is rigidly corrected with the shafts by wedging, screwing or the like and by which part la is arranged to move along the shaft, running in corresponding longitudinal grooves thereon as shown in Fig. 20 with free-wheel 20. The free-wheel 20 in Fig. 20

' is mounted on the main shaft. The free-wheel .is drawn in' a position which is not blocked or free.

In order to displace the gears actuating the blocking action, namely: setting in motion, coupling 22, rods 45 have been arranged above the gears as shown in Figs. 1, 2, 14 and 15. Upon these rods, sleeves 41 have beeniastenedby case of lever 44:: engaging into one or two of the projections by swinging lever 44 in axial direction, the corresponding rod or rods are moved in axial direction also at'the moment end of lever 44a engages therein. On rods 45, by means of pins or some other suitable manner, grip-members 46 have been fastened. As shown in Figs. 1 and 15 a rod 45 has been provided which can be moved in axial direction and belongs to gear 30 which is movable upon the intermediate shaft l0 l8.' An additional rod 45 has been provided which is for the coupling 22. An additional rod '45 has been provided also jointly for both gears l9 and 2| fitted with free-wheel connections. An additional rod 45 is provided for the gear 29 movable upon the intermediate'shaft l8 and still another rod 45 is provided for the displacement of gear shaft 4|.

If, for example, it is desired to change over from the automatic arrangement illustrated in Fig. 1 to maximum reduction (first speed), the

toothed wheels 19 and 2| are so far displaced towards the drivers 3 that they are no longer in engagement with. the toothed wheels l5 and I6 as indicated in Fig. 1 in broken lines, and the toothed wheel 29 is shifted in the same direction as the toothed wheel l9, so far that it comes into mesh with the toothed wheel l5, or the free wheel connection I! is locked, and the toothed wheel 2l'is so displaced that it is no longer in engagement with N5. Further, the clutch 22 is disengaged and the connection between the shaft 5 and the shaft stump 23 and toothed wheel 24 is interrupted. The transmission of power is now eiTected from the shaft stump 23 by way of the toothed wheels 24 and 25, by way of the intermediate shaft 18 and toothed wheel 29, or by way of the toothed wheel I9 provided with the locked free wheel connection, byway of the toothed wheel 15, the hollow again moved into the position it assumes for automatic gear change, so that it is no longer in engagement with I5, and the toothed wheel 30' is so displaced towards the drivers 3 that it comes into engagement with the toothed wheel l6-or the free wheel connection 20 is locked and the toothed wheel I9 is so shifted that it is no longer engagement with the toothed wheel 1 5and the clutch 22 is disengaged so that there is no connection between the shaft 5 and the shaft stump 23 andtoothed wheel'24. The transmission of power is now effected from 23 by way of 24, 25, I8 and 30 or by way of 2|, l6, 8, l0, l2, 3 and 2 to the shaft l. If there is to be effected direct transmission (third speed) by manual operation, the toothed Wheels 29 and 30 remain in the position shown in Fig. 1, but the toothed wheels 19 and 2| are shifted towardsthe drivers 3, so that they are no longer in mesh with I5 and I5, and the clutch 22 is again engaged so that 5 is connected with 23 and 24.

If free wheel running is desired, the toothed wheels on the intermediate shaft are displaced upon another intermediate! I If reverse drive is to be efi'ected, the gearing is set for free wheel running and then one of. the toothed wheels 40, of which one is fixedly mounted on an intermediate shaft 4| and is continuously in mesh in 25-, and of which the other is axially slidable in the grooves 42 or the like on the intermediate shaft 4|, is so shifted that it engages the toothed wheel I5.

The shift of the toothed wheels and the operation of the clutch 22 are effected in known manner by means of grooved hubs 43 which are engaged by the intermediate pieces 45 connected with rods 45 adapted to he slid in axial direction by a change-speed lever 44. When the shift .is effected according to a scheme as shown in Fig. 3 with a gate 41 provided to facilitate manual operation, the displacement of the toothed wheels necessary for each stage or the operation of the clutch can be eifected by means of a single actuation of the lever 44 in this wise that, when the lever 44- engages the notch |),v the gearing is set for automatic operation, two of the rods 45, namely, one for disengaging the clutch 22 and one for shifting the respective toothed wheels being adapted to be displaced by the lever 44; that when the lever 44 engages the notch 5| the gearing is set for direct power transmission;- when the lever 44 engages the notch 52, the gearing is set for second speed; and when the lever.

44 engages the notch 53, the gearing is set for maximum reduction. When the lever 44 engages the notch 54, the gearing is set for reverse drive. When the lever 44 is not in engagement with any of the notches, free wheel running is provided for, it being understood that changeover from one stage to another is efiected with an intermediate free wheel stage.

As illustrated in Fig. 20, the carrier 2 of drivenmember can be provided with an-axial-pressurebearing 50 onto which a lever 5| connects which in turn is connected by a system of rods 52 .and

a. sleeve 53 fastened thereon with the gear-lever 44 itself. The lever 5| engages in between, the

thrust bearing 50 and the cylinder-carrier 2 withits forked end in such a way that upon lever 44 being moved towards position indicated in broken lines parts 53, 52, 5|, and 50 are displaced, the carrier of moving member is lifted up and across the projections l,v l2, and I4, finally reaching the position indicated in broken lines in Fig. 20. In order that the carrier of moving members remain alone in the position in which it has been brought by the actuation of lever 44, notches 52a have been provided on rod 52 into which a spring-pressed bolt 52b may snap. The pressure of the spring exerted upon part 5221, as well as the pitch of the end of the bolt itself are balanced in such a way that the power or force of spring 4 may not lift bolt 521) out from one of the notches 52a. However, if the force of spring 4 is supported by a corresponding axial swaying of lever 44, part 52b shall now be pressed out from notches 52a. However if the driving-mechanism is desired to work automatically, which means an automatic displacement of the carrier of the driving-member 2 by the load, and also the force of spring 4 being used, without axial movement of the carrier 2 by parts 52 and 52b being interfered with, lever 5| is rendered movable in axial direction on rod 52 and there is, as shown in Fig. 20, behind lever. 5| a block-ring 5|a connected with part 52 by pins or some other suitable means, disposed in such a. way whereby upon actuation by hand lever 5| is displaced by the block-ring 5|a in-the on the main shaft itself and in that case the member |'|b belonging to free-wheel 20 is rigidly connected with .the hollow shaft 8, whereas the other member |'|b, belonging to free-wheel I1 is rigidly connected with the hollow shaft 9. Again, the free-wheels in Fig. 20 are blockable as disclosed above, whereby the member |8a belonging to free-wheel 20 is axially movable upon the end part of hollow shaft 8 which is grooved and whereby of free-wheel 11, the inside teeth are provided on the extension 55 which is-ongthe other side of member llb. In order to separate the gear l5 from free-wheel when in reverse, simultaneously connecting with shaft 9 displaced towards the roller 3, such as indicated in broken lines in Fig. 20, a toothed shell 54 has been provided, disposed between hollow shaft 9 and gear 85. said shell being axially and freely movable on hollow shaft 9 having teeth on its outer surface. These teeth shall be engaged .with an insidetoothed ring 56 fastened to hollow shaft 9, effecting by corresponding axial displacement an engagement therewith. This arrangement requires 35 no separate shaft 5 but it may, as seen distinctly from Fig. 20, have the shaft 23 go through the center-bf shaft ,8 and the disc 5 with its projections 1 carried by shaft 23 direct.

In this. case: For automatic change the p0 sition remains unaltered as shown in Fig. for change at will to maximum reduction (first speed) the part 2 is so shifted in the direction of the arrow 21 that the-drivers 3 engage only nection I1 is locked; for change at will to second speed the part 2 is so displaced that the drivers 3 engage only the elevated portions I2 and I4, the free wheel 20 is locked and the toothed wheel the elevated portions I4 and the free wheel con- .5

I5 is so shifted that it is no longer in engage- 4o ment with ii; for change at will to direct power transmission the part 2 is brought to Fig. 20 position so that the drivers engage the elevated portions "I, I2 and l4 and the toothed wheels i5 and I6 are so shifted that theyare no longer a in engagement with 29 or 30; for free wheel 1 running the part 2 is shifted in the direction of the arrow 21, so that the drivers 3 engage none. of the elevated portions I; I2 and I4; for reverse drive the part 2 is so shifted that the drivers 3 m engage only the elevated'portions l4 and the toothedwheels l5 and I6 are'so shifted that they are no longer in engagement with 29 or 30' and one toothed wheel 40 is brought into engagement with l5.

The cams or tappet-like elevated portions 1-, i2 and I4, may, as shown in Figs. 4, 4a and 5, be provided on discs 60, 6|, 62 secured respectively on the shaft 5,,hol1ow shaft 8 and hollow w shaft 9, in which case the drivers 3 acting on the elevated portions or camswill be mounted rockably on rock levers 53 pivoted to the carrier 2.fltted on the shaft l, and the drivers will be subject to the pressure or tension of springs 64 acting on the rock levers 63; In Fig.5 the toothed wheels l5, i6, 24, I9, 2| and 25 are shown arranged in reverse order and size ratio to that of Fig. 1, the shaft I being assumed to v be coupled with the driving motor' and the shaft 5 with the driven mechanism. The devices for effecting variation at will. of the transmission ratio are omitted from the diagrammatic showing of Figs. 4, 4a and 5, the drivers 3 being shown in full lines in the position at maximum load at aredrawn as being made of one piece, further-' more that the discs 80, GI and 82 are shown as being wedged on to shafts 5, 8 and 9 and that the shaft l8 has been formed as one piece together with gear l9. The'free-wheel connections upon the intermediate shaft are illustrated in Fig. 5 in such a way, whereby the free-wheelparts l'lb appear to be freely journalled upon shaft l8 and that the part "b, belonging to freewheel l'l, appears to be rigidly connected with tooth-wheel 2| as well as part llb belonging to free-wheel 20 appears to be rigidly connected with gear 25. Furthermore in Figs. 4a. and 4b, there have been drawn two bored projections 2e attached to part 2, in the boring of which a bolt 2! is secured. On to these bolts 2! are fastened the pivoted levers 63 and springs 84 hooked on to said bolts 2!, as distinctly indicated in Figs. 4a, 4b and.- 5.

The function in that case is exactly as has been described for Fig. 1 and as a matter of fact upon starting, and when under heavy load, at first shaft 5 remains stationary with relation to shaft I, calculated in that case to be connected with the motor when same starts moving at a slower pace than shaft i. Prior to starting, that is to say in unloaded condition, the levers 63 formed as cylinder-carriers, the rollers 3 attachedto it and the springs 84 stay in a position as indicated in Fig. 4a in broken lines. As soon as the load begins to affect the driven shaft 5, the rollers 3 slide along the circumference of discs 60, GI and 82 whereby the springs 84 are brought under tension until the cylinders find themselves above the outer edges l2 of disc 8| and reach the location of curve IA of disc 62. The pitch of parts of curve I4 is so great that the normal momentum of rotation'of the motor is'suflicient in order to overcome the tension of the spring 54 whereby at a corresponding load on the driven shaft, the drivers remain over the curved areas l4 and may only be pressed down towards the middle-shaft if the load is lessened by the aid of springs 64 away from areas |4., As long as the large starting load persists, disc 62 is taken along by rollers 3 and thereby, the rotary movement, by way of hollow-shaft 9 on to the small gear l5 and from here to the large intermediate shaft gear l9 by way of free-wheel IT to 2|, free wheel 20 to gear 25 and, finally, gear 24 engaging into 25, is transferred to shaft 5. It must be mentioned that the free-wheels are constructed in such a way that they function as free-wheels only, that is: free-wheel. l1 transfers no motion from I!) upon 2| and free-wheel 20 no motion from 2| upon 25, only in case when the gear 25 is ahead of gear 2|, if the wheel 2| runs ahead of wheel l9. If the device holds the position as shown in Fig. 4a and there occur in this case loads which represent maximum traction or'any other load impulses whatsoever, the rollers 3 may not slide over surface l4 beyond disc 82 because,

as may be seen in Fig. 4a, levers 63, even if they are only pressed to a small degree by surfaces A I 8 towards the outside, hit against the insidewall of casing 2. In the loaded position, represented in Fig. 4a, shaft 5 turns as a consequence of the transmission of the gears having a low ratio of revolution with a high power ratio. Thereby discs 88 and 8| rotate more rapidly than disc 82 but without touching the rollers 3 a at all because they rotate freely below the rollers close to surface It, also because their highest curved surfaces 1 and it are closer to the middle shaft than the surface it.

In case of the load on the driven shaft growing smaller, levers 63 and therefore rollers 3 are swayed by springs 64 towards the centre-shaft and they firstly engage the slanting surfaces E2 of disc 6|. The surfaces I2 are pitched to such a degree that the load corresponding to the second speed coming off the driven shaft is suffi- 64. The positions held by parts 83, 3 and 64 at medium load, is represented in Fig. 4b. In that case the rotary movement of part 2 by way of parts 83, 3, 8|, 8, [6, 2|, 20, no, 25, 24 .is transferred to shaft 5. The disc 62, in that case, is also carried along by rollers 3 and the rotary movement is transferred from part 9 unto gears I 5 and I9. However, on account of gear 2! in that case rotating more rapidly than gear 19, the effect of free-wheeling is released in freewheel I I whereby the connection between the gears 2i and I9 is released. The rollers 3 are thereby not in contact with the disc 60 because the surfaces I2 are further distant from the centre-point than the highest points I of disc 80.

If the load drops still further the rollers at last begin to grip disc 60 whereby direct transmission upon shaft 5 takes place and the gear 25 rotates more rapidly than 2! and in turn rotates more rapidly than 19, whereby by way of thefree-wheels l1 and'2li, the connection between gears l9, 2| and 25 is released.

The cams or elevated portions 1, l2, 14 may also, as shown in Figs. 6, '7 and 8, be fitted directly to the hollow shafts 8 and 9 or to the shaft 5 having a hollow extension, so that the shafts appear as sleeves the ends of which are provided with open slots, the tappet-like projections or cams being acted on by a pin 10 serving as a driver and secured to an axially movable shaft ll subject to the thrust of the spring 4.

The effect of the driver-bolt l0 opposite to the surfaces I, I2 and M, as well as opposite tothe tooth gears and free-wheels, is in that case equal to that of roller 3 of Figs. 1, 4a, 4b, and 5, description of which is given above.

In correspondence with the number of stages of transmission there will be a number of cam cient in order to surmount. the force of springs discs or sleeves, hollow shafts, etc., so that the nexed claims.

What I claim as my invention and desire to secure by Letters Patent of the United States is:

1. In an automatic change-speed gear having free-wheeling between the transmission speeds, a rotating cam face associated with each speed, each of said cam faces being concentrically disposed with respect to the others and load-connected drivers jointly spring urged against said cam faces, the 'cam faces highest point projecting in each position beyond the cam face of the next higher speed, the steepness of said cam faces being such as to balance the spring effort influencing the drivers for any, given load-transmission ratio.

2. In an automatic change-speed gear having free-wheeling between the transmission speeds, a plurality of concentrically nested cams having peaked faces, one of said cams being associated with each of the transmission speeds, a load connected shaft, an axially movable casing slidable on said shaft, conical drivers mounted radially in said casing and adapted to be progressively engaged by the faces of the cams according to the load on the shaft, and adjustable spring means for urging the drivers against the cams, the faces of said last being such that the load corresponding to the actual transmission ratio the spring effort influencing the driversi position is balanced.

3. In an automatic change-speed gear transmission a load-connected shaft, a driving shaft, a plurality of concentrically nested hollow shafts corresponding in number to the transmission stages, concentrically nested discs provided at one end of the nested hollow shafts and having peaked cam faces, transmission gears mounted on nested hollow said shafts, means for imparting movements to said gears from the driving shaft, a casing slidable on the load-connectedshaft, conical drivers radially mounted in said casing, a spring urging the casing and drivers against the cam faces of the discs, and means for adjusting the tension of the spring.

4. In .an automatic change-speed gear as claimed in claim 3, free-wheeling means inserted in the transmission stages, an intermediate shaft supporting said free-wheeling means in meshing arrangement with the transmission gears, a gear for imparting a reduced rotary movement to the intermediate shaft from the driving shaft, a disengageable' clutch on the driving shaft, means for locking the free-wheeling means, and fork means for slidably displacing the transmission gears axially on the intermediate shaft, whereby manual shifting of the gears can be eflectuated at will independently of the automatic means by manipulation of a conventional shifting lever cooperating with said fork means.

5. In an automatic change speed transmis= sion, a driven load-connected shaft, a plurality of concentrically aligned shafts co-axial with the driven shaft, a cup-shaped peaked cam at the load end of each shaft, said cams being con= centrically nested one wi the other e 1-: :1.

central shaft.

ing faces increasing in steepnss'from the innermost cam to the outermost one, a drum axially slidable on the driven shaft and splined thereto,

conical drivers radially secured to said drum for contacting with the cam faces, an adjustable spring urging the drum and drivers against the cams, a gear connected to the other end of each shaft except the innermost one, a countershaft parallel to the shafts, gears on said countershaft meshing with the gears of the shafts, freewheeling units between the countershaft and each of its gears, a driving shaft geared to said countershaft, and a clutch for effectuating direct drive between said driving shaft and the inner 6. An automatic gear transmission, comprising driving and driven shafts, a countershaft, gearing between the driving shaft and said countershaft, whereby said last is continuously drivenby the driving shaft, a plurality of shafts concentrically disposed with respect to each other and each protruding from within the next outer 'ers and connected to the driven shaft, and'a clutch between the central concentric shaft and the driving shaft. 1 7. In an automatic gear transmission having a driving shaft geared to a countershaft, said countershaft including speed reducing gears provided with free-wheelings, a plurality of shafts concentrically nested and having one end provided with a gear meshing with one of the countershaft concentric shaft, said. cams beingconcentrically disposed with respect to each other, spring pressed means adapted to successively press shaft, a gear on the free end of each shaft ex-.

v gears,-a cup-shaped cam at the other end of each 4 against said cams according to the load to be' transmitted through the transmissioma loadconnected driven shaft connected to the springpressed means, and a clutch for connecting said inner shaft to the driving shaft. 

